There is the conventional technology of letting a device retain a plurality of application programs (which will be referred to hereinafter as “applications”) and permitting only a specific application to make access to data. For example, Patent Document 1 described below discloses a method of applying this technology to IC cards, so as to solve the security problem and achieve effective utilization of a memory. This Patent Document 1 discloses such a technological feature that an IC card permits a plurality of applications to share a predetermined data area. The Patent Document 1 is Japanese Patent Application Laid-Open Gazette No. Heisei 8-190614.